while True:
    print('Enter your age:')
    age = input()
    if age.isdecimal():
        break
    else:
        print('Please enter a number for your age !')

while True:
    print('Enter your password:')
    password = input()
    if password.isalnum():
        print('Password saved!')
        break
    else:
        print('Enter letters and numbers, please !')
